Impact of Nonylphenol on Antioxidant System and Acetylcholinesterase Activity in the Brain of Etroplus Maculatus (Bloch, 1795)

Abstract

Nonylphenol, an environmental contaminant, is widely released into the aquatic ecosystem are also known to affect non-target animals. The present study focused on the impact of nonylphenol on the antioxidant system and acetylcholinesterase activity in the brain of Etroplus maculatus. Fishes were exposed to sublethal concentrations (1/5^th and 1/10^th of LC₅₀) of nonylphenol for 24, 72 and 96 h. The results showed that nonylphenol treatment significantly (P<0.05) increased the activities of superoxide dismutase and catalase, however, glutathione reductase activity was decreased significantly in all treatment groups when compared to the control groups. The level of hydrogen peroxide generation and lipid peroxidation increased significantly (P<0.05) in concentration- and time-dependant manner.  Acetylcholinesterase activity was used as biomarker to assess the toxicity effect of nonylphenol and it was found that the enzyme activity was decreased significantly at both sublethal concentrations in time-dependant manner, which revealed the neurotoxic effect of the contaminant. The results hence confirmed that nonylphenol caused significant disturbances in the antioxidant enzyme system and acetylcholinesterase activity in the brain of Etroplus maculatus. Thus, the current study provides better information on the potential toxic effects of nonylphenol on aquatic animals, especially to fish.